Backrest for wheelchair

Abstract

A backrest for a wheelchair includes an adjustable cushion support, a backrest frame, and attachment members. The adjustable cushion support supports a backrest cushion, and substantially defines plane P 1. The backrest frame holds the cushion support and has two substantially parallel side posts substantially defining a plane P 2. The attachment members attach the cushion support to the backrest frame. The cushion support comprises two side bars and a plurality of transversally extending and vertically spaced apart flexible straps. Each strap is length adjustable. The cushion support comprises at least two connecting plates. Each plate being integral with one of the side bars and being provided with at least two parallel adjustment slots. The slots define an angle α, with said plane P 1 of the adjustable support cushion. The attachment members are slidably mounted on the slots, enabling depth, width and angular adjustment of the cushion support on the backrest frame.

The invention claimed is: 
     
       1. A backrest for a wheelchair, comprising:
 an adjustable cushion support, for supporting a backrest cushion, said cushion support defining substantially a first plane P 1 ; 
 a backrest frame, for holding said cushion support, said backrest frame having two substantially parallel first side posts defining substantially a second plane P 2 ; 
 attachment members, for attaching said cushion support to said backrest frame; 
 said cushion support comprising two side bars and a plurality of transversally extending and vertically spaced apart flexible straps each interconnecting said two side bars, each being adjustable in length; 
 said cushion support comprising at least two connecting plates, each plate being integral with one of said side bars and being provided with at least two parallel adjustment slots, said slots defining an angle α, with said first plane P 1 ; 
 said attachment members being slidably mounted on said slots, enabling depth, width and angular adjustment of said cushion support on said brackrest frame; and wherein the angle lies between 30° and 60°. 
 
     
     
       2. A backrest according to  claim 1 , wherein said attachment members consist in bolts or screws adapted to be threadedly received in threaded holes formed inside the first side posts of the backrest frame. 
     
     
       3. A backrest according to  claim 2 , wherein the parallel slots are large enough to allow said bolts or screws to pivot as a group in said slots without being removed from said slots. 
     
     
       4. A backrest according to  claim 2 , wherein the first side posts of the backrest frame are provided with a series of threaded holes adapted to threadedly receive said attachment members, enabling height adjustment of said cushion support on said backrest frame. 
     
     
       5. A backrest according to  claim 1 , wherein the angle α is approximately equal to 45°. 
     
     
       6. A backrest according to  claim 5 , wherein the length of the parallel slots is approximately equal to 35 mm. 
     
     
       7. A backrest according to  claim 1 , wherein the length of the parallel slots lies between 10 mm and 50 mm. 
     
     
       8. A backrest according to  claim 1 , wherein Velcro fasteners are provided on one side of the straps and complementary Velcro fasteners are provided on the other side of the straps for adjusting the length of the straps. 
     
     
       9. A backrest according to  claims 1 , wherein the side bars of the cushion support are bent in at least two places, thus defining at least three successive straight sections. 
     
     
       10. A backrest according to  claim 1 , wherein the backrest frame comprises a first U-shape element and a second U-shape element, said first U-shape element comprising said two first side posts linked at their lower ends by a connection profile and said second U-shape element comprising two second side posts linked at their upper ends by a connection profile, said first and second elements being clamped together by upper clamping elements and lower clamping elements. 
     
     
       11. A backrest according to  claim 10 , wherein each clamping element consists in a plate bent at its two ends so as to define an internal space inside which one of the first side posts of the first U-shape element and the corresponding one of said second side posts of the second U-shape element are tightly disposed. 
     
     
       12. A backrest according to  claim 11 , wherein said upper clamping elements are respectively positioned along the first side posts of the first U-shape element so as to cover a section of said first side posts comprising a series of threaded holes adapted to threadedly receive said attachment members, said upper clamping elements comprising a series of corresponding holes adapted to receive said attachment members. 
     
     
       13. A backrest according to  claim 10 , wherein said upper clamping elements are respectively positioned along the first side posts of the first U-shape element so as to cover a section of said first side posts comprising a series of threaded holes adapted to threadedly receive said attachment members, said upper clamping elements comprising a series of corresponding holes adapted to receive said attachment members. 
     
     
       14. A wheelchair having a backrest according to  claim 1 .